What is a cation and where can you find it on the periodic table? What is an anion and where can you find it on the periodic table?

A cation is an ion with fewer electrons than protons. Therefore, it has a positive charge. The electric charge on a proton is equal in amount to the charge on an electron. Anions are atoms or radicals (groups of atoms), that have gained electrons. Since they now have more electrons than protons, anions have a negative charge. Halogens always form anions, alkali metals and alkaline earth metals always form cations. Most other metals form cations (e.g. iron, silver, nickel), whilst most other nonmetals typically form anions (e.g. oxygen, carbon, sulfur).

Explanation:

An anion and cation cannot be specifically found on the periodic table.    

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.